The eastern United States is home to over a dozen hickory tree species, all belonging to the genus Carya.
Two of the most common are the shagbark hickory (Carya ovata) and the pignut hickory (Carya glabra).
While similar in some respects, these two hickories have distinctive differences when it comes to appearance, preferred habitat, uses, and even the flavor of their nuts.
- Shagbark hickory is distinguished by its shaggy bark that peels away in vertical strips, while pignut hickory has tight, ridged bark.
- Shagbark nuts are rounded, while pignut nuts are oval-shaped.
- Shagbark hickory can tolerate a wider variety of habitats, including moist bottomlands. Pignut prefers drier uplands.
- The wood of both trees is strong and flexible, good for products like tool handles and furniture. Shagbark is considered to have a more rustic look.
- Shagbark nuts are arguably more flavorful, with notes of maple syrup, while pignut can be bitter.
- Hickory nuts from both trees provide an important food source for wildlife.
- As towering giants in eastern forests, hickories contribute to ecosystem health through services like wildlife food and habitat in decaying wood.
- While related and overlapping in range, shagbark and pignut hickories have distinct differences that add richness and diversity to the forests they inhabit.
Appearance and Bark
The most obvious visual difference between shagbark and pignut hickories lies in their bark.
As the name implies, shagbark hickory has a loose, shaggy bark that peels away from the trunk in long, vertical strips.
The bark starts out smooth and tight but begins shredding as the tree matures. Pignut hickory, on the other hand, maintains its tight, ridged bark throughout its lifespan.
The two trees can also be distinguished by their nuts and leaves. Shagbark nuts are more rounded, while pignut nuts have a more elongated, oval shape.
Shagbark leaves usually have five leaflets, while pignut leaves typically have three to five.
Overall, pignut hickories tend to have a more slender crown shape compared to the broader, rounded crown of the shagbark.
Habitat and Range
Both shagbark and pignut hickories are found throughout the eastern United States, ranging from southern Ontario and Maine down to Florida and over to eastern Texas.
However, they tend to thrive in slightly different environments.
Shagbark hickory is a bit more flexible when it comes to habitat.
It can grow in drier upland areas like ridge tops and slopes but also thrives in moist bottomlands near streams.
Pignut hickory is more abundant on dry, sandy ridges and hillsides or rocky open woodlands. It is also a common hickory species found along stream banks.
In terms of climate, shagbark tolerates colder conditions better than pignut.
It can be found up into Canada while the pignut reaches its northern limit in southern Michigan and Pennsylvania.
Both types of hickory wood are strong, tough, and flexible. This makes them ideal for products like tool handles, athletic equipment, furniture, and flooring.
Shagbark hickory is sometimes preferred for its coarser, more rustic look.
The sweet nuts of both trees are also edible and enjoyed by people and wildlife.
They can be eaten raw or used in recipes.
Historically, Native Americans utilized parts of both trees. Shagbark hickory was prized for bows and arrow shafts, as the long strips of bark could be used for lacings.
Pignut shells were used decoratively by some tribes. The high oil content of hickory nuts also made their wood good for fuel.
Today, shagbark and pignut nuts are still harvested from wild trees.
Cultivated varieties and hybrids have also been developed for commercial nut production.
There is some debate as to whether shagbark or pignut hickory nuts taste better. Both provide the distinctive rich, sweet, smoky hickory flavor.
However, shagbarks are thought to be more flavorful with notes of maple syrup. Pignuts tend to be smaller with a slightly bitter taste.
They require leaching to remove the pungent odors.
Some experts attribute the differences to the higher sap content of the pignut.
Others believe climate and soil conditions impact the taste and that there are also variations among individual trees.
There certainly seems to be more agreement around the superior flavor of shagbark nuts.
As large, long-lived trees, both shagbark and pignut hickories play important ecological roles in eastern forests.
Their nuts provide food for wildlife including squirrels, chipmunks, deer, bears, foxes, raccoons, and birds.
Gray squirrels in particular rely on hickory nuts for winter survival.
Slow-growing and decay-resistant, the wood of fallen hickories can persist on the forest floor for years.
Over time, this dead wood becomes habitat for mosses, insects, and fungi. Shirley rot fungus assists with hickory decomposition.
Young shagbarks and pignuts may even sprout from stumps or roots of felled trees.
While pests like the hickory bark beetle may attack unhealthy trees, healthy shagbarks and pignuts have few serious insect or disease issues.
They live long lives, typically 150 to 400 years. These icons of eastern forests continue enriching the ecosystem cycle after cycle.